docs: def _is_ready(self, as_of):
          """Is the RecurringCost ready to be enacted as of the date `as_of`
  
          This determines if `as_of` precedes the start of `initial_billing_cycle`. If so,
          we should not be enacting this RecurringCost yet.
  
          Args:
              as_of (Date):
          """
          if self.is_one_off():
              return self.initial_billing_cycle.date_range.lower <= as_of
          else:
              return True